Regge-cascade hadronization

We argue that the evolution of coloured partons into colour-singlet hadrons has approximate factorization into an extended parton-shower phase and a colour-singlet resonance–pole phase. The amplitude for the conversion of colour connected partons into hadrons necessarily resembles Regge-pole amplitudes since qq̄ resonance amplitudes and Regge-pole amplitudes are related by duality. A ‘Regge-cascade’ factorization property of the N-point Veneziano amplitude provides further justification of this protocol. This latter factorization property, in turn, allows the construction of general multi-hadron amplitudes in amplitude-squared factorized form from (1 → 2) link amplitudes. We suggest an algorithm with cascadedecay configuration, ordered in the transverse momentum, suitable for Monte-Carlo simulation. We make a simple implementation of this procedure in Herwig++, obtaining some improvement to the description of the event-shape distributions at LEP. PACS. 12.38.Aw General properties of QCD – 12.40.Nn Regge theory, duality, absorptive/optical models – 13.87.Fh Fragmentation into hadrons